The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Software in general is sold directly off-line on media including CD-ROMs and DVD-ROMs, or downloaded for payments by the consumers through the software maker's Internet venue. For the software buyer/user to install the product and use it, it is necessary to input a provided software authenticating CD-key in the individual terminal whereby the software maker legitimately authorizes the use of the product.
However, due to the bare exposure of the CD-keys in the form of common text they are helplessly copied along with the CD-ROM contents over and over for liberal services to illegitimate third parties. With no bother to search for a CD-key, they reach to employ an extra illegal CD-key generating program or a cracking method into the CD-key authenticating program itself to eventually hack the legitimate copy authentication process even letting P2P sites to uncontrollably distribute among people and thus fatally defeating many efforts to protect the software copyrights.
There is a counter measure that provides the CD-ROM or DVD-ROM at a certain track with authentication information for exclusively permitting the operation of the stored program which in effect incorporates the physical presence of the legitimate medium in the user terminal, but a cracking method to remove the pertinent authentication section from the software body was found to effectively defeat the protection.
In response, an extra hardware device was provided for attachment to a terminal port for printer or a USB port so that its presence is checked or the device is arranged to store encrypting/decoding key values and algorithm until the encrypted code is decoded at the software execution. However, the structural limitation having software at execution be decoded before it gets loadable into the terminal memory allows bypassing the protection scheme to hack into the software frequently and offers an open chance for even the nonprofessional general public to use an available automatic hacking tool to actually commit violations of the copy protection technologies the harder as they get more popular. Besides, virtual machines were used trying to thwart reverse engineering attempts and protect the identifying logic for the authentication key to software, but history shows actual hackings and distributions of automatic hacking tools.